zeyneph I know this is a few days late, but it's worth answering anyway for future reference.
If the sim you deleted was a carpool driver, it might not harm your save. If it was a resident, I would absolutely quit without saving. The problem, as described above, doesn't get fixed by the game itself, but sims without much data attached to them are less likely to cause problems.
As always, having NRaas ErrorTrap and Overwatch helps clean up stray data, but the mods don't catch everything. And if you do delete a sim and don't want to quit without saving, a MasterController Total Annihilation, run after the fact, would take care of any issues, provided MC can still find the sim to delete.
Since this thread is several years old now, I'll lock it here.
